Hi JavaFan, great answer, albeit an obvious one, but that begets more questions then. The "environment" in which the language runs becomes the restriction then. For some reason, the environment in which the server side languages run (the entire operating system) is just the opposite of restrictive.

And, for all the love and talk of open, we are perfectly happy with having a Hobson's Choice of only JavaScript on the browser side simply because the browser vendors choose to not cooperate beyond compatibility with JavaScript. Why isn't that alternative browsers have developed then? Ones that could offer alternatives to JavaScript? Perhaps, a Perl browser that implements a fully first class Perl implementation inside it. Perhaps, a Java or a Python browser.

Why don't you write such a browser and make it so good it displaces all the other common browsers out there now to become the leader of the pack that everything else follows?

This is not a question of open standards or anything of that sort, but of the historical growth of pretty much all the internet related technologies. The same sort of thing has happened many times in very many different areas. Consider Betamax and VHS for example or more recently Blu-ray Disc and HD DVD, or television video formats, or screw head types, or ... . Any place where there are trade offs affecting implementation and adoption that result in incompatible systems there tends to be a variant that succeeds and everything else falls by the wayside. That's just market forces at work and often has very little to do with the technical qualities of the technologies involved.

So all you have to do is convince all the browser suppliers and all web content providers that Perl should be the client side scripting language, or write a browser that is so much better than everything else that you can enforce your own will, and that particular part of the world is your oyster.

Alternative browsers haven't been developed? I'd say, alternative browsers have been developed ever since the early 1990s. It started with a couple of line mode browsers. Then Mosaic. From Mosaic, Netscape was developed. W3C came with Arena. Microsoft entered the market with IE. Netscape became Mozilla, which became Firefox. Opera came. Apple developed Safari. Google has Chrome. And there are numerous lesser know browsers.

Ones that could offer alternatives to JavaScript?

I guess none of the browser makers in the past saw any advantage. Perhaps I should bounce the question back: why haven't you created an alternative?

Ones that could offer alternatives to JavaScript?

But why? Don't forget, there are more than a billion users of browsers who will never ever write HTML let alone any embedded code. Most browser vendors will have a business model - they don't employ a development team just for the fun of it.

Perhaps, a Java or a Python browser.

Both done in the previous century: Hot Java and Grail. But Joe R. User just wants a browser that works with his computers, and which is preferable the same one as he uses in his office, and which his neighbour is using.

And why shouldn't he? Why would he care whether his browser is capable of running Python scripts?

To be specific, after failing to license Netscape Navigator, Microsoft built IE out of the existing Spyglass Mosaic project, which licensed non-code stuff from NSCA Mosaic, on which Netscape was originally based (well, both were Andreessen's projects). It's interesting how connected it all was at the start, and how quickly they tend to diverge and converge over time.